libhb/reader.c

   1 /* $Id: reader.c,v 1.21 2005/11/25 15:05:25 titer Exp $
   2
   3    This file is part of the HandBrake source code.
   4    Homepage: <http://handbrake.fr/>.
   5    It may be used under the terms of the GNU General Public License. */
   6
   7 #include "hb.h"
   8
   9 typedef struct
  10 {
  11     double average; // average time between packets
  12     int64_t last;   // last timestamp seen on this stream
  13     int id;         // stream id
  14     int is_audio;   // != 0 if this is an audio stream
  15     int valid;      // Stream timing is not valid until next scr.
  16 } stream_timing_t;
  17
  18 typedef struct
  19 {
  20     hb_job_t     * job;
  21     hb_title_t   * title;
  22     volatile int * die;
  23
  24     hb_bd_t      * bd;
  25     hb_dvd_t     * dvd;
  26     hb_stream_t  * stream;
  27
  28     stream_timing_t *stream_timing;
  29     int64_t        scr_offset;
  30     hb_psdemux_t   demux;
  31     int            scr_changes;
  32     uint32_t       sequence;
  33     uint8_t        st_slots;        // size (in slots) of stream_timing array
  34     uint8_t        saw_video;       // != 0 if we've seen video
  35     uint8_t        saw_audio;       // != 0 if we've seen audio
  36
  37     int            start_found;     // found pts_to_start point
  38     uint64_t       st_first;
  39 } hb_reader_t;
  40
  41 /***********************************************************************
  42  * Local prototypes
  43  **********************************************************************/
  44 static void        ReaderFunc( void * );
  45 static hb_fifo_t ** GetFifoForId( hb_job_t * job, int id );
  46 static void UpdateState( hb_reader_t  * r, int64_t start);
  47
  48 /***********************************************************************
  49  * hb_reader_init
  50  ***********************************************************************
  51  *
  52  **********************************************************************/
  53 hb_thread_t * hb_reader_init( hb_job_t * job )
  54 {
  55     hb_reader_t * r;
  56
  57     r = calloc( sizeof( hb_reader_t ), 1 );
  58
  59     r->job   = job;
  60     r->title = job->title;
  61     r->die   = job->die;
  62     r->sequence = 0;
  63
  64     r->st_slots = 4;
  65     r->stream_timing = calloc( sizeof(stream_timing_t), r->st_slots );
  66     r->stream_timing[0].id = r->title->video_id;
  67     r->stream_timing[0].average = 90000. * (double)job->vrate_base /
  68                                            (double)job->vrate;
  69     r->stream_timing[0].last = -r->stream_timing[0].average;
  70     r->stream_timing[0].valid = 1;
  71     r->stream_timing[1].id = -1;
  72
  73     if ( !job->pts_to_start )
  74         r->start_found = 1;
  75
  76     return hb_thread_init( "reader", ReaderFunc, r,
  77                            HB_NORMAL_PRIORITY );
  78 }
  79
  80 static void push_buf( const hb_reader_t *r, hb_fifo_t *fifo, hb_buffer_t *buf )
  81 {
  82     while ( !*r->die && !r->job->done )
  83     {
  84         if ( hb_fifo_full_wait( fifo ) )
  85         {
  86             hb_fifo_push( fifo, buf );
  87             break;
  88         }
  89     }
  90 }
  91
  92 static int is_audio( hb_reader_t *r, int id )
  93 {
  94     int i;
  95     hb_audio_t *audio;
  96
  97     for( i = 0; ( audio = hb_list_item( r->title->list_audio, i ) ); ++i )
  98     {
  99         if ( audio->id == id )
 100         {
 101             return 1;
 102         }
 103     }
 104     return 0;
 105 }
 106
 107 // The MPEG STD (Standard Target Decoder) essentially requires that we keep
 108 // per-stream timing so that when there's a timing discontinuity we can
 109 // seemlessly join packets on either side of the discontinuity. This join
 110 // requires that we know the timestamp of the previous packet and the
 111 // average inter-packet time (since we position the new packet at the end
 112 // of the previous packet). The next four routines keep track of this
 113 // per-stream timing.
 114
 115 // find the per-stream timing state for 'buf'
 116
 117 static stream_timing_t *find_st( hb_reader_t *r, const hb_buffer_t *buf )
 118 {
 119     stream_timing_t *st = r->stream_timing;
 120     for ( ; st->id != -1; ++st )
 121     {
 122         if ( st->id == buf->id )
 123             return st;
 124     }
 125     return NULL;
 126 }
 127
 128 // find or create the per-stream timing state for 'buf'
 129
 130 static stream_timing_t *id_to_st( hb_reader_t *r, const hb_buffer_t *buf, int valid )
 131 {
 132     stream_timing_t *st = r->stream_timing;
 133     while ( st->id != buf->id && st->id != -1)
 134     {
 135         ++st;
 136     }
 137     // if we haven't seen this stream add it.
 138     if ( st->id == -1 )
 139     {
 140         // we keep the steam timing info in an array with some power-of-two
 141         // number of slots. If we don't have two slots left (one for our new
 142         // entry plus one for the "-1" eol) we need to expand the array.
 143         int slot = st - r->stream_timing;
 144         if ( slot + 1 >= r->st_slots )
 145         {
 146             r->st_slots *= 2;
 147             r->stream_timing = realloc( r->stream_timing, r->st_slots *
 148                                         sizeof(*r->stream_timing) );
 149             st = r->stream_timing + slot;
 150         }
 151         st->id = buf->id;
 152         st->average = 30.*90.;
 153         st->last = -st->average;
 154         if ( ( st->is_audio = is_audio( r, buf->id ) ) != 0 )
 155         {
 156             r->saw_audio = 1;
 157         }
 158         st[1].id = -1;
 159         st->valid = valid;
 160     }
 161     return st;
 162 }
 163
 164 // update the average inter-packet time of the stream associated with 'buf'
 165 // using a recursive low-pass filter with a 16 packet time constant.
 166
 167 static void update_ipt( hb_reader_t *r, const hb_buffer_t *buf )
 168 {
 169     stream_timing_t *st = id_to_st( r, buf, 1 );
 170     double dt = buf->renderOffset - st->last;
 171     // Protect against spurious bad timestamps
 172     if ( dt > -5 * 90000LL && dt < 5 * 90000LL )
 173     {
 174         st->average += ( dt - st->average ) * (1./32.);
 175         st->last = buf->renderOffset;
 176     }
 177     st->valid = 1;
 178 }
 179
 180 // use the per-stream state associated with 'buf' to compute a new scr_offset
 181 // such that 'buf' will follow the previous packet of this stream separated
 182 // by the average packet time of the stream.
 183
 184 static void new_scr_offset( hb_reader_t *r, hb_buffer_t *buf )
 185 {
 186     stream_timing_t *st = id_to_st( r, buf, 1 );
 187     int64_t last;
 188     if ( !st->valid )
 189     {
 190         // !valid means we've not received any previous data
 191         // for this stream.  There is no 'last' packet time.
 192         // So approximate it with video's last time.
 193         last = r->stream_timing[0].last;
 194         st->valid = 1;
 195     }
 196     else
 197     {
 198         last = st->last;
 199     }
 200     int64_t nxt = last + st->average;
 201     r->scr_offset = buf->renderOffset - nxt;
 202     // This log is handy when you need to debug timing problems...
 203     //hb_log("id %x last %ld avg %g nxt %ld renderOffset %ld scr_offset %ld",
 204     //    buf->id, last, st->average, nxt, buf->renderOffset, r->scr_offset);
 205     r->scr_changes = r->demux.scr_changes;
 206     st->last = nxt;
 207 }
 208
 209 /***********************************************************************
 210  * ReaderFunc
 211  ***********************************************************************
 212  *
 213  **********************************************************************/
 214 static void ReaderFunc( void * _r )
 215 {
 216     hb_reader_t  * r = _r;
 217     hb_fifo_t   ** fifos;
 218     hb_buffer_t  * buf;
 219     hb_list_t    * list;
 220     int            n;
 221     int            chapter = -1;
 222     int            chapter_end = r->job->chapter_end;
 223
 224     if ( r->title->type == HB_BD_TYPE )
 225     {
 226         if ( !( r->bd = hb_bd_init( r->title->path ) ) )
 227             return;
 228     }
 229     else if ( r->title->type == HB_DVD_TYPE )
 230     {
 231         if ( !( r->dvd = hb_dvd_init( r->title->path ) ) )
 232             return;
 233     }
 234     else if ( r->title->type == HB_STREAM_TYPE )
 235     {
 236         if ( !( r->stream = hb_stream_open( r->title->path, r->title ) ) )
 237             return;
 238     }
 239     else
 240     {
 241         // Unknown type, should never happen
 242         return;
 243     }
 244
 245     hb_buffer_t *ps = hb_buffer_init( HB_DVD_READ_BUFFER_SIZE );
 246     if (r->bd)
 247     {
 248         if( !hb_bd_start( r->bd, r->title ) )
 249         {
 250             hb_bd_close( &r->bd );
 251             hb_buffer_close( &ps );
 252             return;
 253         }
 254         if ( r->job->start_at_preview )
 255         {
 256             // XXX code from DecodePreviews - should go into its own routine
 257             hb_bd_seek( r->bd, (float)r->job->start_at_preview /
 258                          ( r->job->seek_points ? ( r->job->seek_points + 1.0 ) : 11.0 ) );
 259         }
 260         else if ( r->job->pts_to_start )
 261         {
 262             hb_bd_seek_pts( r->bd, r->job->pts_to_start );
 263         }
 264         else
 265         {
 266             hb_bd_seek_chapter( r->bd, r->job->chapter_start );
 267         }
 268         if (r->job->angle > 1)
 269         {
 270             hb_bd_set_angle( r->bd, r->job->angle - 1 );
 271         }
 272     }
 273     else if (r->dvd)
 274     {
 275         /*
 276          * XXX this code is a temporary hack that should go away if/when
 277          *     chapter merging goes away in libhb/dvd.c
 278          * map the start and end chapter numbers to on-media chapter
 279          * numbers since chapter merging could cause the handbrake numbers
 280          * to diverge from the media numbers and, if our chapter_end is after
 281          * a media chapter that got merged, we'll stop ripping too early.
 282          */
 283         int start = r->job->chapter_start;
 284         hb_chapter_t *chap = hb_list_item( r->title->list_chapter, chapter_end - 1 );
 285
 286         chapter_end = chap->index;
 287         if (start > 1)
 288         {
 289            chap = hb_list_item( r->title->list_chapter, start - 1 );
 290            start = chap->index;
 291         }
 292         /* end chapter mapping XXX */
 293
 294         if( !hb_dvd_start( r->dvd, r->title, start ) )
 295         {
 296             hb_dvd_close( &r->dvd );
 297             hb_buffer_close( &ps );
 298             return;
 299         }
 300         if (r->job->angle)
 301         {
 302             hb_dvd_set_angle( r->dvd, r->job->angle );
 303         }
 304
 305         if ( r->job->start_at_preview )
 306         {
 307             // XXX code from DecodePreviews - should go into its own routine
 308             hb_dvd_seek( r->dvd, (float)r->job->start_at_preview /
 309                          ( r->job->seek_points ? ( r->job->seek_points + 1.0 ) : 11.0 ) );
 310         }
 311     }
 312     else if ( r->stream && r->job->start_at_preview )
 313     {
 314
 315         // XXX code from DecodePreviews - should go into its own routine
 316         hb_stream_seek( r->stream, (float)( r->job->start_at_preview - 1 ) /
 317                         ( r->job->seek_points ? ( r->job->seek_points + 1.0 ) : 11.0 ) );
 318
 319     }
 320     else if ( r->stream && r->job->pts_to_start )
 321     {
 322         int64_t pts_to_start = r->job->pts_to_start;
 323
 324         // Find out what the first timestamp of the stream is
 325         // and then seek to the appropriate offset from it
 326         if ( hb_stream_read( r->stream, ps ) )
 327         {
 328             if ( ps->start > 0 )
 329                 pts_to_start += ps->start;
 330         }
 331
 332         if ( hb_stream_seek_ts( r->stream, pts_to_start ) >= 0 )
 333         {
 334             // Seek takes us to the nearest I-frame before the timestamp
 335             // that we want.  So we will retrieve the start time of the
 336             // first packet we get, subtract that from pts_to_start, and
 337             // inspect the reset of the frames in sync.
 338             r->start_found = 2;
 339             r->job->pts_to_start = pts_to_start;
 340         }
 341     }
 342     else if( r->stream )
 343     {
 344         /*
 345          * Standard stream, seek to the starting chapter, if set, and track the
 346          * end chapter so that we end at the right time.
 347          */
 348         int start = r->job->chapter_start;
 349         hb_chapter_t *chap = hb_list_item( r->title->list_chapter, chapter_end - 1 );
 350
 351         chapter_end = chap->index;
 352         if (start > 1)
 353         {
 354             chap = hb_list_item( r->title->list_chapter, start - 1 );
 355             start = chap->index;
 356         }
 357
 358         /*
 359          * Seek to the start chapter.
 360          */
 361         hb_stream_seek_chapter( r->stream, start );
 362     }
 363
 364     list  = hb_list_init();
 365
 366     while( !*r->die && !r->job->done )
 367     {
 368         if (r->bd)
 369             chapter = hb_bd_chapter( r->bd );
 370         else if (r->dvd)
 371             chapter = hb_dvd_chapter( r->dvd );
 372         else if (r->stream)
 373             chapter = hb_stream_chapter( r->stream );
 374
 375         if( chapter < 0 )
 376         {
 377             hb_log( "reader: end of the title reached" );
 378             break;
 379         }
 380         if( chapter > chapter_end )
 381         {
 382             hb_log( "reader: end of chapter %d (media %d) reached at media chapter %d",
 383                     r->job->chapter_end, chapter_end, chapter );
 384             break;
 385         }
 386
 387         if (r->bd)
 388         {
 389           if( !hb_bd_read( r->bd, ps ) )
 390           {
 391               break;
 392           }
 393         }
 394         else if (r->dvd)
 395         {
 396           if( !hb_dvd_read( r->dvd, ps ) )
 397           {
 398               break;
 399           }
 400         }
 401         else if (r->stream)
 402         {
 403           if ( !hb_stream_read( r->stream, ps ) )
 404           {
 405             break;
 406           }
 407           if ( r->start_found == 2 )
 408           {
 409             // We will inspect the timestamps of each frame in sync
 410             // to skip from this seek point to the timestamp we
 411             // want to start at.
 412             if ( ps->start > 0 && ps->start < r->job->pts_to_start )
 413                 r->job->pts_to_start -= ps->start;
 414             else if ( ps->start >= r->job->pts_to_start )
 415                 r->job->pts_to_start = 0;
 416             r->start_found = 1;
 417           }
 418         }
 419
 420         if( r->job->indepth_scan )
 421         {
 422             /*
 423              * Need to update the progress during a subtitle scan
 424              */
 425             hb_state_t state;
 426
 427 #define p state.param.working
 428
 429             state.state = HB_STATE_WORKING;
 430             p.progress = (double)chapter / (double)r->job->chapter_end;
 431             if( p.progress > 1.0 )
 432             {
 433                 p.progress = 1.0;
 434             }
 435             p.rate_avg = 0.0;
 436             p.hours    = -1;
 437             p.minutes  = -1;
 438             p.seconds  = -1;
 439             hb_set_state( r->job->h, &state );
 440         }
 441
 442         (hb_demux[r->title->demuxer])( ps, list, &r->demux );
 443
 444         while( ( buf = hb_list_item( list, 0 ) ) )
 445         {
 446             hb_list_rem( list, buf );
 447             fifos = GetFifoForId( r->job, buf->id );
 448
 449             if ( fifos && ! r->saw_video && !r->job->indepth_scan )
 450             {
 451                 // The first data packet with a PTS from an audio or video stream
 452                 // that we're decoding defines 'time zero'. Discard packets until
 453                 // we get one.
 454                 if ( buf->start != -1 && buf->renderOffset != -1 &&
 455                      ( buf->id == r->title->video_id || is_audio( r, buf->id ) ) )
 456                 {
 457                     // force a new scr offset computation
 458                     r->scr_changes = r->demux.scr_changes - 1;
 459                     // create a stream state if we don't have one so the
 460                     // offset will get computed correctly.
 461                     id_to_st( r, buf, 1 );
 462                     r->saw_video = 1;
 463                     hb_log( "reader: first SCR %"PRId64" id %d DTS %"PRId64,
 464                             r->demux.last_scr, buf->id, buf->renderOffset );
 465                 }
 466                 else
 467                 {
 468                     fifos = NULL;
 469                 }
 470             }
 471             if( fifos )
 472             {
 473                 if ( buf->renderOffset != -1 )
 474                 {
 475                     if ( r->scr_changes != r->demux.scr_changes )
 476                     {
 477                         // This is the first audio or video packet after an SCR
 478                         // change. Compute a new scr offset that would make this
 479                         // packet follow the last of this stream with the
 480                         // correct average spacing.
 481                         stream_timing_t *st = id_to_st( r, buf, 0 );
 482
 483                         // if this is the video stream and we don't have
 484                         // audio yet or this is an audio stream
 485                         // generate a new scr
 486                         if ( st->is_audio ||
 487                              ( st == r->stream_timing && !r->saw_audio ) )
 488                         {
 489                             new_scr_offset( r, buf );
 490                         }
 491                         else
 492                         {
 493                             // defer the scr change until we get some
 494                             // audio since audio has a timestamp per
 495                             // frame but video & subtitles don't. Clear
 496                             // the timestamps so the decoder will generate
 497                             // them from the frame durations.
 498                             if ( st != r->stream_timing )
 499                             {
 500                                 // not a video stream so it's probably
 501                                 // subtitles - the best we can do is to
 502                                 // line it up with the last video packet.
 503                                 buf->start = r->stream_timing->last;
 504                             }
 505                             else
 506                             {
 507                                 buf->start = -1;
 508                                 buf->renderOffset = -1;
 509                             }
 510                         }
 511                     }
 512                 }
 513                 if ( buf->start != -1 )
 514                 {
 515                     int64_t start = buf->start - r->scr_offset;
 516                     if ( !r->start_found )
 517                         UpdateState( r, start );
 518
 519                     if ( !r->start_found &&
 520                         r->job->pts_to_start &&
 521                         buf->renderOffset != -1 &&
 522                         start >= r->job->pts_to_start )
 523                     {
 524                         // pts_to_start point found
 525                         // force a new scr offset computation
 526                         stream_timing_t *st = find_st( r, buf );
 527                         if ( st &&
 528                             (st->is_audio ||
 529                             ( st == r->stream_timing && !r->saw_audio ) ) )
 530                         {
 531                             // Re-zero our timestamps
 532                             st->last = -st->average;
 533                             new_scr_offset( r, buf );
 534                             r->start_found = 1;
 535                             r->job->pts_to_start = 0;
 536                         }
 537                     }
 538                     // This log is handy when you need to debug timing problems
 539                     //hb_log("id %x scr_offset %ld start %ld --> %ld",
 540                     //        buf->id, r->scr_offset, buf->start,
 541                     //        buf->start - r->scr_offset);
 542                     buf->start -= r->scr_offset;
 543                 }
 544                 if ( buf->renderOffset != -1 )
 545                 {
 546                     if ( r->scr_changes == r->demux.scr_changes )
 547                     {
 548                         // This packet is referenced to the same SCR as the last.
 549                         // Adjust timestamp to remove the System Clock Reference
 550                         // offset then update the average inter-packet time
 551                         // for this stream.
 552                         buf->renderOffset -= r->scr_offset;
 553                         update_ipt( r, buf );
 554                     }
 555                 }
 556                 if ( !r->start_found )
 557                 {
 558                     hb_buffer_close( &buf );
 559                     continue;
 560                 }
 561
 562                 buf->sequence = r->sequence++;
 563                 /* if there are mutiple output fifos, send a copy of the
 564                  * buffer down all but the first (we have to not ship the
 565                  * original buffer or we'll race with the thread that's
 566                  * consuming the buffer & inject garbage into the data stream). */
 567                 for( n = 1; fifos[n] != NULL; n++)
 568                 {
 569                     hb_buffer_t *buf_copy = hb_buffer_init( buf->size );
 570                     hb_buffer_copy_settings( buf_copy, buf );
 571                     memcpy( buf_copy->data, buf->data, buf->size );
 572                     push_buf( r, fifos[n], buf_copy );
 573                 }
 574                 push_buf( r, fifos[0], buf );
 575             }
 576             else
 577             {
 578                 hb_buffer_close( &buf );
 579             }
 580         }
 581     }
 582
 583     // send empty buffers downstream to video & audio decoders to signal we're done.
 584     if( !*r->die && !r->job->done )
 585     {
 586         push_buf( r, r->job->fifo_mpeg2, hb_buffer_init(0) );
 587
 588         hb_audio_t *audio;
 589         for( n = 0; (audio = hb_list_item( r->job->title->list_audio, n)); ++n )
 590         {
 591             if ( audio->priv.fifo_in )
 592                 push_buf( r, audio->priv.fifo_in, hb_buffer_init(0) );
 593         }
 594
 595         hb_subtitle_t *subtitle;
 596         for( n = 0; (subtitle = hb_list_item( r->job->title->list_subtitle, n)); ++n )
 597         {
 598             if ( subtitle->fifo_in && subtitle->source == VOBSUB)
 599                 push_buf( r, subtitle->fifo_in, hb_buffer_init(0) );
 600         }
 601     }
 602
 603     hb_list_empty( &list );
 604     hb_buffer_close( &ps );
 605     if (r->bd)
 606     {
 607         hb_bd_stop( r->bd );
 608         hb_bd_close( &r->bd );
 609     }
 610     else if (r->dvd)
 611     {
 612         hb_dvd_stop( r->dvd );
 613         hb_dvd_close( &r->dvd );
 614     }
 615     else if (r->stream)
 616     {
 617         hb_stream_close(&r->stream);
 618     }
 619
 620     if ( r->stream_timing )
 621     {
 622         free( r->stream_timing );
 623     }
 624
 625     hb_log( "reader: done. %d scr changes", r->demux.scr_changes );
 626     if ( r->demux.dts_drops )
 627     {
 628         hb_log( "reader: %d drops because DTS out of range", r->demux.dts_drops );
 629     }
 630
 631     free( r );
 632     _r = NULL;
 633 }
 634
 635 static void UpdateState( hb_reader_t  * r, int64_t start)
 636 {
 637     hb_state_t state;
 638     uint64_t now;
 639     double avg;
 640
 641     now = hb_get_date();
 642     if( !r->st_first )
 643     {
 644         r->st_first = now;
 645     }
 646
 647 #define p state.param.working
 648     state.state = HB_STATE_SEARCHING;
 649     p.progress  = (float) start / (float) r->job->pts_to_start;
 650     if( p.progress > 1.0 )
 651     {
 652         p.progress = 1.0;
 653     }
 654     if (now > r->st_first)
 655     {
 656         int eta;
 657
 658         avg = 1000.0 * (double)start / (now - r->st_first);
 659         eta = ( r->job->pts_to_start - start ) / avg;
 660         p.hours   = eta / 3600;
 661         p.minutes = ( eta % 3600 ) / 60;
 662         p.seconds = eta % 60;
 663     }
 664     else
 665     {
 666         p.rate_avg = 0.0;
 667         p.hours    = -1;
 668         p.minutes  = -1;
 669         p.seconds  = -1;
 670     }
 671 #undef p
 672
 673     hb_set_state( r->job->h, &state );
 674 }
 675 /***********************************************************************
 676  * GetFifoForId
 677  ***********************************************************************
 678  *
 679  **********************************************************************/
 680 static hb_fifo_t ** GetFifoForId( hb_job_t * job, int id )
 681 {
 682     hb_title_t    * title = job->title;
 683     hb_audio_t    * audio;
 684     hb_subtitle_t * subtitle;
 685     int             i, n, count;
 686     static hb_fifo_t * fifos[100];
 687
 688     memset(fifos, 0, sizeof(fifos));
 689
 690     if( id == title->video_id )
 691     {
 692         if( job->indepth_scan )
 693         {
 694             /*
 695              * Ditch the video here during the indepth scan until
 696              * we can improve the MPEG2 decode performance.
 697              */
 698             return NULL;
 699         }
 700         else
 701         {
 702             fifos[0] = job->fifo_mpeg2;
 703             return fifos;
 704         }
 705     }
 706
 707     n = 0;
 708     count = hb_list_count( title->list_subtitle );
 709     count = count > 99 ? 99 : count;
 710     for( i=0; i < count; i++ ) {
 711         subtitle =  hb_list_item( title->list_subtitle, i );
 712         if (id == subtitle->id) {
 713             subtitle->hits++;
 714             if( !job->indepth_scan || job->select_subtitle_config.force )
 715             {
 716                 /*
 717                  * Pass the subtitles to be processed if we are not scanning, or if
 718                  * we are scanning and looking for forced subs, then pass them up
 719                  * to decode whether the sub is a forced one.
 720                  */
 721                 fifos[n++] = subtitle->fifo_in;
 722             }
 723         }
 724     }
 725     if ( n != 0 )
 726     {
 727         return fifos;
 728     }
 729
 730     if( !job->indepth_scan )
 731     {
 732         n = 0;
 733         for( i = 0; i < hb_list_count( title->list_audio ); i++ )
 734         {
 735             audio = hb_list_item( title->list_audio, i );
 736             if( id == audio->id )
 737             {
 738                 fifos[n++] = audio->priv.fifo_in;
 739             }
 740         }
 741
 742         if( n != 0 )
 743         {
 744             return fifos;
 745         }
 746     }
 747
 748     return NULL;
 749 }
 750